Double-barreled automatic gun



P. R. HlGsoN 2,509,734

3 ShebS-Sheel'. l

DOUBLE-BARRELED AUTOMTIC GUN May 30, 1950 Filed sept. Yles, 1947 Q Q HHH UJT f Y www f u m P uw. 1| lll l |ll| May 30, 1950 P. R. HlGsoN nouBLE-BARRELED AUTOMATIC GUN 3 Sheets-Sheet 3 Filed Sept. 16, 1947 S Y mw/Jmwlml/ WMM' HCTFA/Ts Patented May 30, 1950 DOUBLE-BARRELED AUTMATIC GUN Application September 16, 1947, Serial No. 774,327 In Great Britain September 17, 1946 8 Claims.

This invention relates to automatic guns and is applicable inter alia to automatic guns of the barrel individually experiences a rate of re which is half that of the gun.

Preferably, the locking of each breech block in the ring position is obtained with the aid of a lever that can swing from a position where it locks one breech block, to a position where it locks the other breech block.` The swinging movement of said lever can be brought about by the recoil and run-out of the breech block which is not locked thereby, so that on completion of the run-out of the unlocked breech block, the.

level1 completes a swinging movement whereby it locks the hitherto unlocked breech bioch and releases the other for recoil and run-out in continuation of the cyclic locking action oi the lever.

For a better understanding of the nature of the invention and to show how the same may be carried into eiect reference will now be made to the accompanying drawings in which,

Figure l is a plan View of a machine gun from which the cartridge feed mechanism and other parts have been removed, to show the breech mechanism in detail,

Figure 2 is a longitudinal section taken on the line II-II of Figure 1, as seen in the direction of the arrows shown in Figure 1,

Figure 3 is a section on the line III-III of Figure 2', as seen in the direction of the arrows,

Figure 4 is a plan similar to Figure l but showing a different operative position of the breech mechanism,

Figure 5 is a skeleton plan similar to Figure 4 but showing a further operative position of the mechanism,

Figure 6 is an underneath plan of the breech mechanism showing a detail of the mechanism thereof, and

Figure '7 is a plan of the breech. end oi the gun, showing the feed mechanism thereof.

Referring first to Figures 1, 2, 3 and 6, it will be observed that the gun has a breech casing including a bottom plate l and side plates 2. There are two barrels 3 and i and 'similarly two breech blocks 5 and t. The breech blocks are of similar construction and are both adapted to slide longitudinally within the breech casing. The side plates i! are grooved and permit hand cooking handles l and 8 to protrude therethrough. Each cooking handle is elTectively integral with its associated breech blocks, and light recoil springs 9 and It serve to hold the breech blocks in their forward position illustrated in Figure l.

The base plate l of the breech casing 'carries a stud Il upon which is pivotally supported a lever l2. The latter can Swing upon its pivotal support, the free end being tapered as seen in plan so as to be engageable with either breech block 5 or 6. The stud ii' is supported indirectly by a vertical lug l lA which forms a seating for the boss of the lever l2. To accommodate the free tapered end of the lever` i2, each breech block has a cut away portion leaving a rearwardly extending part i3, i4 and a transversely ei:- tending part l5, IS. In Figure l, the free end of the lever l2 is showing engaging behind the transverse part i5 of the breech block 5'. As seen best in Figure 2, the free end of the lever l2 has a downward extension il' acting as 'a iinger for engagement in an arcuate slot i8, provided in the base plate member l. The arcuate slot i8 is, of course, centred about the pivot vII of the lever l2, so that the lever can freely move about its pivot. Each transverse part I5 and 4I5 of the breech blocks, has a firing pin (not shown) located therein, the ring pins being operable by mechanism located in the free end of the lever I2, as at l'9. A protruding head 2U is arranged so that when the head is depressed 'with the lever l2 in the positionvshown in .Figure 1, the firing pin of the breech block 5 is brought into operation. It will be comprehended that whenk'the lever l2 is swung to the opposite position where it engages the breech block 6, depresssion of the head 20 will then result in the operation oi the ring pin associated with the breech block 6.'

The underside of the lever l2 has an island cam 2l for engagement with a cam pintle 22', It will be observed from Figure 1 thatthe island cam 2l is triangular in shape with the apex of the triangle directed towards the pivotal Asupport of the lever I2. The upper end i23 of the cam pintle 22 is also of generally4 triangular shape as seen in plan, the apex being, however, directed oppositely in regard to the apenv of the island cam 2|. The pintle 22 passes through the base niember I of the breech casing and has a plate 24 secured to it. The underneath plan view in Figure 6, shows the plate 24 and it will be observed that it possesses a biiurcated end 25 permitting the plate to be displaced to a position where the bifurcated end lies around an anchor post 25. The latter is pivotally carried in the base member I' and grips one end of a rod 2 the other end of which passes freely through the lower end of the cam pintle 22. A spring 28A is located over the rod 21 and tends to urge the pintle forwardly together with its plate 24 (the direction forwardly refers to the direction towards the right in Fig. 2 i. e. from the rear of the gun towards the barrels thereof). The plate 24 can both slide and also move angularly about the anchor pivot 25, and is guided in suitably formed facing grooves in two strips 23 and 2e secured to the underside of the base member l (see Fig. 6)

A hammer bar 35 lies transversely within the breech casing and is guided in a recess 3| formed in the base member I. It will be noted that either end of the hammer bar 35 is radiused, and the recess 3l is correspondingly shaped so that the bar fits within the recess 3l when the bar lies completely transversely to the longitudinal aXis of the gun, as shown in Figure 1. The recess 3| has two curvilinear sides 32 and 33 which permit the hammer bar 3B to be swung about either end towards a position where it lies more nearly along the axis of the gun. The thin platform produced by provision of the recess 3l, is cut away to form a slot 34 through which the cam pintle A22 projects. It will be noted irom Figure 1, that the slot 34 is of approximately triangular shape, the base being however, curvilinear in general continuation of the curvilinear sides 32 and 33 of the recess 3l. The apex of the triangular slot 34 finishes in a short straight slot 34A dimensioned so that the cam pintle 22 can t therein.

In the constructional example illustrated, it is supposed that the gun is gas operated. A double gas-block 40 is provided, each individual gasblock communicating with the'interior of one of the barrels 3 and 4 of the gun. The double block houses two gas pistons 4I and 42 which both bear against the end of a rod 43. The latter is provided with a roller 44 which engages a transverse bar 45 havinga pin 45 which may enter a slot 4l. Each end of the bar 45 -is formed with a nose 48 located in an associated slide block 49. The forward end of each breech block 5 and 5 bears against the rearward end of one of the slide blocks 49.

The springs 9 and I0 associated with the Ybreech blocks will serve to keep the bar 43 in contact with the gas pistons 4l, since both such springs urge their breech blocks forwardly and hence correspondingly influence the slide blocks 49.

There is known trigger` mechanism associated I with the gun, and so far as it is necessary to an understanding of the invention, this is shown in Figures 1 and 2. It will be observed that there are two sears 5B' and 5I commonly carried upon a shaft which can be angularly adjusted by a Y level` arm 52. A spring plunger 53 passes the lever arm 52 downwardly (see Fig. 2) and there is a leaf spring 54 associated with each sear. Either sear can be lowered against the action of its associated spring 54, but normally occupies the position shown in Figure 2. The rearward end of eachv of the breech blocks 5 and 5 is provided with a recess 55 which can engage upon the appropriate sear 50 or 5I.

The gun so far described is intended to be ied with rounds of ammunition from a belt. The feed mechanism which will be briefly described hereinafter, is generally of known kind and the operation of the breech mechanism of the gun will now be described without consideration of the ammunition feed. In Figure 1 the operative position of the gun is shown where both the breech blocks 5 and 6 are in their forward position i. e. they lie against the breech ends of the barrels. It will be supposed that the gun is unloaded. It will thus be noted that the breech block 5 is locked against rearward movement for the reason that the free end of the lever I2 is engaging behind the transverse part I5 of the breech block 5. The breech block 5 is however, free to be moved rearwardly.

If the breech block B is drawn back by the use of the cooking handle 1, the recess 55 can be engaged over the sear 5I Vin the manner shown in Figure 4. The breech block 5 will be retained in this position by the sear against the action of the spring 9 which is now extended. During the initial movement of the breech block 5 towards its rearward position, the transverse part I5 thereof encounters the bar 3i). It causes the bar 30 to be swung around one end until it reaches the position shown in Figure 4. Movement towards this position of the bar 3D, causes the latter to encounter the campintle 22, the upper end 23 of which rides along the adjacent side of the island cam 2l. Hence the cam pintle 22 is`carried backwardly against the action of its spring 28A. When the end 23 of the pintle reaches the apex of the island cam, further movements of the bar 30 causes the pintle to swing in anticlockwise direction (as viewed in Figures 1 and 4) so that it is no longer in line with the side of the island cam on which it formerly rode. It will be observed that the bar 30 has recesses 30A at each end. These recesses are formed in such manner that each breech block may pass over the end of the bar whilst contacting the inner face of the recess. As shown in Figure 4, hcwever, the last part of the rearward movement I of the breech does not result in freeing the bar 3l), the effect being only to allow the bar to remain stationary with the breech block passing over the inner face of the recess 30A.

With the breech block B in the position where j it is engaged upon the sear 5I (Figure 4), the

Vbreech end of the barrel 4.Y

iirst round of ammunition can be loaded into the The. gun is now cocked, and if the lever 52 is raised, the sear 5I is disengaged from the Vbreech block 6 and the latter runs forward under the action of its spring Y l, 9. During this forward movement however, after an initial period when the transverse part I 6 and soY recess 30A are co-operating, the bar 3D will begin to swing rapidly back towards its initial position. The pintle 22 will move alsov forwardly, and will ride along the adjacent edge of its slot 35. In so doing however, the upper end V23 of the pintle will engage the other side of the island cam 2I and will therefore force the island cam and the lever I2 carrying thersame to be swung rapidly in a clockwise direction towards the pothe appropriate breech block is locked before the hammer bar contacts the firing head 2B. The round in the barrel 4 is thus fired. rl'fne firing ci the round causes the gas piston l2 to move axially and thereby displace the bar G3 rearwardly. The roller 44 contacts the cross bar l5 and rocks the latter about the now locked breech block G, thereby displacing the slider block gli) rearwardly. This rearward displacement causes the breech block 5 to be recoiled forcibly, and a series of operations continues in the manner described following the cooking operation. The description with reference to Figure 4 concerning the cool:- ing operation assumed that neither oi the gas pistons had operated. In Figure i there is shown the case however, where the gas piston d! has operated and has caused the cross bar i5 to swing to the position where it has forcibly thrust the breech block 6 rearwardly.

It will be understood that so long as the sears 50 and 5| are kept in the position where they will not pick up either breech block, the gun will continue to operate firing alternately first from the one barrel and then from the other. Each breech block remains locked in the iiring position from i the time just before firing takes place until the gas piston associated with the barrel operates and causes the other breech block to be recoiled. It will of course, be necessary to provide for extraction and ejection of the rounds, and this may be carried out by methods usual with machine guns. It is convenient to work the feed slide for an ammunition belt from the movements of the bar 43. There may be two feed pawls 6% of standard design associated with a slide block 6 l. The usual pawl 62 for preventing reverse feed may also be provided (see Fig. 3). The slide 5l is moved transversely across the breech. mechanism by a lever 63 pivotecl intermediate its ends in the breech casing (see Figs. 2 and 7). The lever t3 is engaged by an arm Se of a bell-crank, the other arm S5 of which engages a pin 6B that may conveniently be the pin upon which the roller 44 is mounted. As will be clear from Figure '7,

when either of the gas pistons ill' or 52 moves rearwardly, then the displacement of the bar i3 results in a swinging of the bell-crank with the consequence that the feed slide 5! is moved. For each complete reciprocation ci the feed slide 5I, the ammunition belt is advanced by a distance equal to the space between the rounds carried in the belt. It will be noted from Figure 3 that the distance between the axes of the rounds is equal to half the distance between the axes of the barrels of the gun. Since the belt traverses only the distance between the rounds on each complete reciprocation of the feed slide l, it will be clear that there will always be a round ready for extraction from the belt to produce an appropriate feed to the barrel that is to fire. Pivoted or retractable feed-pieces 'lll of any well-known type are carried upon each breech block and serve to bring a round into the firing position as the breech block moves forward on the run-out. During recoil the used cartridge case is withdrawn from the chamber in the usual manner, and can be ejected through ejection apertures 'il provided in the base member of the breech casing It may be found desirable in practice to cushion the last part of the recoil of each breech block. For this purpose there is shown in Figure l, stops 80 which operate against springs 8l enclosed in a suitable casing at the rear end of the breech mechanism. There are other refinements which 'may be carried out in constructing a guniollowing the principles of the invention, but such relinements have not been shown in the drawings since they do not strictly form part of the present invention and would render the drawings more diiiicult to follow. It has further to be understood that the principles of the invention could be applied to guns which mechanically operate from the recoil and not from gas pressures derived from the red barrels. If so desired the barrels can be rendered easily replaceable in the manner common with air-cooled guns. If however, the gun of the invention is iired at a normal rate then it will at once be realised that each barrel operates at only half the normal rate and hence the wear will be correspondingly reduced and the tendency for the barrels to heat will also be reduced. This permits the possibility of longer bursts of fire. The invention is of course, particularly applicable to automatic small arms but each breech block ior iiring the barrel whose breech is ocked in the iiring position, means responsive to the ring of a barrel to produce a force tending to cause recoil of both locked and unlocked breech blocks with respect to their barrels,

such force being effective only upon the unlocked block, and means associated with each breech `block for displacing said locking device on the run-out of the unlocked block to cause said device to be displaced to lock the running-out block in the firing position and thereby to unlock the other block for recoil.

2. A double-barrelled automatic gun for` alternate firing from each barrel, comprising a reech block for each barrel, slideways allowing each said breech block to slide relative to the associated barrel towards and away from the firing position, a lever, a pivotal anchorage for said lever at one end thereof to permit the other free end of said lever to be swingable between two positions, a locking face upon each breech block against which said other free end of said lever can engage and lock when the breech block is in the ring position, firing means for firing the barrel whose breech is locked in the firing positionV by said lever, means responsive to the firing of a barrel to produce a force tending to cause recoil of both the locked and unlocked breech blocks with respect to their barrels, such force being effective only upon the unlocked block, and means associated with each block for displacing said lever on the run-out of the unlocked block to cause said lever to be displaced to engage the locking face of the running-out block in the firing position thereof.

3. A double-barrelled automatic gun as claimed in claim 2, in which said means associated with each block for displacing said lever on the runout of the unlocked block, comprise a member arranged to contact both the breech blocks thereby to experience the movement of either, cam faces upon said lever, and a pintle for engagement with said cam faces, said pintle being contacted by said member in order that the pintle should experience movement depending upon movement of either breech block, the pintle serving to displace said lever through the cam faces thereof.

4. A double-barrelled automatic gun for alternate ring from each barrel, comprising a breech block for each barrel, each such breech block being slidable towards and away from the firing position, a lever, a pivotal anchorage at one end of said lever at a location substantially midway between the axes of the two barrels of the gun, a face upon the free end of said lever capable of engaging behind either breech block thereby to lock the same in the ring position, cam faces upon said lever in the form of an island cam of triangular shape directed with its apex towards the said pivotal anchorage, a cam pintle for engaging the divergent cam faces upon said lever, guiding means for same cam pintle to ensure that movement of'the cam pintle includes a component extending along a median of the triangular island cam as drawn from the said apex thereof, a displaceable member disposed behind said breech blocks and in eiective contact therewith to experience displacement from either, said member being eiectively in contact with said cam pintle to produce movements thereof for the swinging of said lever, ring means for firing the barrel whose breech is locked in the ring position, and means responsive to the firing of a barrel to produce a force tending to cause recoil of both said breech blocks but effective to cause only the unlocked block to recoil.

5. A double-barrelled automatic gun according to claim 4, in which the guiding means for said cam pintle consist of the margins of a cutout portion shaped substantially triangularly with its apex directed oppositely to that of the island cam, and further comprising spring means which urge the cam pintle towards the apex of the cut-out portion.

6. A double-barrelled automatic gun according to claim 4, and further 'comprising a platform, bounding walls about said platform to form a recess ior accommodation of said member, such bounding walls being shaped to permit said member to lie transversely with respect to the barrel axes whilst being capable of making pivotal movements about either of its ends according to which breech block recoils.

7. A double-barrelled automatic gun according to claim 6, and further comprising a ring head carried by said lever at the free end thereof, and ring means on each breech block, such firing head being arranged to co-operate with said ring means of either breech block when said lever is locking a breech block in the firing position, said member being formed as a hammer bar for co-operation with said firing head.

8. A double-barrelled automatic gun for alternate firing from each barrel, comprising a breech block for each barrel, each breech block being slidable towards and away from the firing position, a displaceable locking device capable of alternately occupying either of two positions in each of which it positively locks the one or the other of the breech blocks in the ring position, firing means for firing the barrel whose breech is locked in the firing position, a centrally pivoted cross-bar, a [connection between one breech block and one end of said centrally pivoted cross-bar, a second connection between the other breech block and the other end of said centrally pivoted cross-bar, an element disposed to recoil against said pivoted cross-bar on the firing of either barrel, thereby eiectively to displace the pivot thereof to cause recoiling of whichever breech block is unlocked, and means associated with each breech block for displacing said locking device on the run-out of the unlocked block, to cause said device to be displaced to lock the runningout block in the ring position.

PERCY REUBEN HIGSON.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 390,114 Burton Sept. 25, 1888 623,003 Garland Apr. 11, 1899 960,825 Colleoni June 7, 1910 1,055,759 Knotgen Mar. 11, 1913 1,351,017 Blackmore Aug. 31, 1920 1,477,115 Gast Dec, 11, 1923 2,167,495 Wimmersperg July 25, 1939 FOREIGN PATENTS Number Country Date 704,123 France Feb. 17, 1931 

